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<a name="Timing-Utilities"></a>
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<p>
Next: <a href="Filesystem-Utilities.html#Filesystem-Utilities" accesskey="n" rel="next">Filesystem Utilities</a>, Up: <a href="System-Utilities.html#System-Utilities" accesskey="u" rel="up">System Utilities</a> [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Concept-Index.html#Concept-Index" title="Index" rel="index">Index</a>]</p>
</div>
<hr>
<a name="Timing-Utilities-1"></a>
<h3 class="section">36.1 Timing Utilities</h3>
<p>Octave’s core set of functions for manipulating time values are
patterned after the corresponding functions from the standard C library.
Several of these functions use a data structure for time that includes
the following elements:
</p>
<dl compact="compact">
<dt><code>usec</code></dt>
<dd><p>Microseconds after the second (0-999999).
</p>
</dd>
<dt><code>sec</code></dt>
<dd><p>Seconds after the minute (0-60). This number can be 60 to account
for leap seconds.
</p>
</dd>
<dt><code>min</code></dt>
<dd><p>Minutes after the hour (0-59).
</p>
</dd>
<dt><code>hour</code></dt>
<dd><p>Hours since midnight (0-23).
</p>
</dd>
<dt><code>mday</code></dt>
<dd><p>Day of the month (1-31).
</p>
</dd>
<dt><code>mon</code></dt>
<dd><p>Months since January (0-11).
</p>
</dd>
<dt><code>year</code></dt>
<dd><p>Years since 1900.
</p>
</dd>
<dt><code>wday</code></dt>
<dd><p>Days since Sunday (0-6).
</p>
</dd>
<dt><code>yday</code></dt>
<dd><p>Days since January 1 (0-365).
</p>
</dd>
<dt><code>isdst</code></dt>
<dd><p>Daylight saving time flag.
</p>
</dd>
<dt><code>gmtoff</code></dt>
<dd><p>Seconds offset from UTC.
</p>
</dd>
<dt><code>zone</code></dt>
<dd><p>Time zone.
</p></dd>
</dl>
<p>In the descriptions of the following functions, this structure is
referred to as a <var>tm_struct</var>.
</p>
<a name="XREFtime"></a><dl>
<dt><a name="index-time"></a><em><var>seconds</var> =</em> <strong>time</strong> <em>()</em></dt>
<dd><p>Return the current time as the number of seconds since the epoch.
</p>
<p>The epoch is referenced to 00:00:00 UTC (Coordinated Universal Time) 1 Jan
1970. For example, on Monday February 17, 1997 at 07:15:06 UTC, the value
returned by <code>time</code> was 856163706.
</p>
<p><strong>See also:</strong> <a href="#XREFstrftime">strftime</a>, <a href="#XREFstrptime">strptime</a>, <a href="#XREFlocaltime">localtime</a>, <a href="#XREFgmtime">gmtime</a>, <a href="#XREFmktime">mktime</a>, <a href="#XREFnow">now</a>, <a href="#XREFdate">date</a>, <a href="#XREFclock">clock</a>, <a href="#XREFdatenum">datenum</a>, <a href="#XREFdatestr">datestr</a>, <a href="#XREFdatevec">datevec</a>, <a href="#XREFcalendar">calendar</a>, <a href="#XREFweekday">weekday</a>.
</p></dd></dl>
<a name="XREFnow"></a><dl>
<dt><a name="index-now"></a><em>t =</em> <strong>now</strong> <em>()</em></dt>
<dd><p>Return the current local date/time as a serial day number
(see <code>datenum</code>).
</p>
<p>The integral part, <code>floor (now)</code> corresponds to the number of days
between today and Jan 1, 0000.
</p>
<p>The fractional part, <code>rem (now, 1)</code> corresponds to the current time.
</p>
<p><strong>See also:</strong> <a href="#XREFclock">clock</a>, <a href="#XREFdate">date</a>, <a href="#XREFdatenum">datenum</a>.
</p></dd></dl>
<a name="XREFctime"></a><dl>
<dt><a name="index-ctime"></a><em></em> <strong>ctime</strong> <em>(<var>t</var>)</em></dt>
<dd><p>Convert a value returned from <code>time</code> (or any other non-negative
integer), to the local time and return a string of the same form as
<code>asctime</code>.
</p>
<p>The function <code>ctime (time)</code> is equivalent to
<code>asctime (localtime (time))</code>. For example:
</p>
<div class="example">
<pre class="example">ctime (time ())
⇒ "Mon Feb 17 01:15:06 1997\n"
</pre></div>
<p><strong>See also:</strong> <a href="#XREFasctime">asctime</a>, <a href="#XREFtime">time</a>, <a href="#XREFlocaltime">localtime</a>.
</p></dd></dl>
<a name="XREFgmtime"></a><dl>
<dt><a name="index-gmtime"></a><em><var>tm_struct</var> =</em> <strong>gmtime</strong> <em>(<var>t</var>)</em></dt>
<dd><p>Given a value returned from <code>time</code>, or any non-negative integer,
return a time structure corresponding to UTC (Coordinated Universal Time).
</p>
<p>For example:
</p>
<div class="example">
<pre class="example">gmtime (time ())
⇒ {
usec = 0
sec = 6
min = 15
hour = 7
mday = 17
mon = 1
year = 97
wday = 1
yday = 47
isdst = 0
gmtoff = 0
zone = GMT
}
</pre></div>
<p><strong>See also:</strong> <a href="#XREFstrftime">strftime</a>, <a href="#XREFstrptime">strptime</a>, <a href="#XREFlocaltime">localtime</a>, <a href="#XREFmktime">mktime</a>, <a href="#XREFtime">time</a>, <a href="#XREFnow">now</a>, <a href="#XREFdate">date</a>, <a href="#XREFclock">clock</a>, <a href="#XREFdatenum">datenum</a>, <a href="#XREFdatestr">datestr</a>, <a href="#XREFdatevec">datevec</a>, <a href="#XREFcalendar">calendar</a>, <a href="#XREFweekday">weekday</a>.
</p></dd></dl>
<a name="XREFlocaltime"></a><dl>
<dt><a name="index-localtime"></a><em><var>tm_struct</var> =</em> <strong>localtime</strong> <em>(<var>t</var>)</em></dt>
<dd><p>Given a value returned from <code>time</code>, or any non-negative integer,
return a time structure corresponding to the local time zone.
</p>
<div class="example">
<pre class="example">localtime (time ())
⇒ {
usec = 0
sec = 6
min = 15
hour = 1
mday = 17
mon = 1
year = 97
wday = 1
yday = 47
isdst = 0
gmtoff = -21600
zone = CST
}
</pre></div>
<p><strong>See also:</strong> <a href="#XREFstrftime">strftime</a>, <a href="#XREFstrptime">strptime</a>, <a href="#XREFgmtime">gmtime</a>, <a href="#XREFmktime">mktime</a>, <a href="#XREFtime">time</a>, <a href="#XREFnow">now</a>, <a href="#XREFdate">date</a>, <a href="#XREFclock">clock</a>, <a href="#XREFdatenum">datenum</a>, <a href="#XREFdatestr">datestr</a>, <a href="#XREFdatevec">datevec</a>, <a href="#XREFcalendar">calendar</a>, <a href="#XREFweekday">weekday</a>.
</p></dd></dl>
<a name="XREFmktime"></a><dl>
<dt><a name="index-mktime"></a><em><var>seconds</var> =</em> <strong>mktime</strong> <em>(<var>tm_struct</var>)</em></dt>
<dd><p>Convert a time structure corresponding to the local time to the number of
seconds since the epoch.
</p>
<p>For example:
</p>
<div class="example">
<pre class="example">mktime (localtime (time ()))
⇒ 856163706
</pre></div>
<p><strong>See also:</strong> <a href="#XREFstrftime">strftime</a>, <a href="#XREFstrptime">strptime</a>, <a href="#XREFlocaltime">localtime</a>, <a href="#XREFgmtime">gmtime</a>, <a href="#XREFtime">time</a>, <a href="#XREFnow">now</a>, <a href="#XREFdate">date</a>, <a href="#XREFclock">clock</a>, <a href="#XREFdatenum">datenum</a>, <a href="#XREFdatestr">datestr</a>, <a href="#XREFdatevec">datevec</a>, <a href="#XREFcalendar">calendar</a>, <a href="#XREFweekday">weekday</a>.
</p></dd></dl>
<a name="XREFasctime"></a><dl>
<dt><a name="index-asctime"></a><em></em> <strong>asctime</strong> <em>(<var>tm_struct</var>)</em></dt>
<dd><p>Convert a time structure to a string using the following
format: <code>"ddd mmm mm HH:MM:SS yyyy\n"</code>.
</p>
<p>For example:
</p>
<div class="example">
<pre class="example">asctime (localtime (time ()))
⇒ "Mon Feb 17 01:15:06 1997\n"
</pre></div>
<p>This is equivalent to <code>ctime (time ())</code>.
</p>
<p><strong>See also:</strong> <a href="#XREFctime">ctime</a>, <a href="#XREFlocaltime">localtime</a>, <a href="#XREFtime">time</a>.
</p></dd></dl>
<a name="XREFstrftime"></a><dl>
<dt><a name="index-strftime"></a><em></em> <strong>strftime</strong> <em>(<var>fmt</var>, <var>tm_struct</var>)</em></dt>
<dd><p>Format the time structure <var>tm_struct</var> in a flexible way using the format
string <var>fmt</var> that contains ‘<samp>%</samp>’ substitutions similar to those in
<code>printf</code>.
</p>
<p>Except where noted, substituted fields have a fixed size; numeric fields are
padded if necessary. Padding is with zeros by default; for fields that
display a single number, padding can be changed or inhibited by following
the ‘<samp>%</samp>’ with one of the modifiers described below. Unknown field
specifiers are copied as normal characters. All other characters are copied
to the output without change. For example:
</p>
<div class="example">
<pre class="example">strftime ("%r (%Z) %A %e %B %Y", localtime (time ()))
⇒ "01:15:06 AM (CST) Monday 17 February 1997"
</pre></div>
<p>Octave’s <code>strftime</code> function supports a superset of the ANSI C field
specifiers.
</p>
<p>Literal character fields:
</p>
<dl compact="compact">
<dt><code>%%</code></dt>
<dd><p>% character.
</p>
</dd>
<dt><code>%n</code></dt>
<dd><p>Newline character.
</p>
</dd>
<dt><code>%t</code></dt>
<dd><p>Tab character.
</p></dd>
</dl>
<p>Numeric modifiers (a nonstandard extension):
</p>
<dl compact="compact">
<dt><code>- (dash)</code></dt>
<dd><p>Do not pad the field.
</p>
</dd>
<dt><code>_ (underscore)</code></dt>
<dd><p>Pad the field with spaces.
</p></dd>
</dl>
<p>Time fields:
</p>
<dl compact="compact">
<dt><code>%H</code></dt>
<dd><p>Hour (00-23).
</p>
</dd>
<dt><code>%I</code></dt>
<dd><p>Hour (01-12).
</p>
</dd>
<dt><code>%k</code></dt>
<dd><p>Hour (0-23).
</p>
</dd>
<dt><code>%l</code></dt>
<dd><p>Hour (1-12).
</p>
</dd>
<dt><code>%M</code></dt>
<dd><p>Minute (00-59).
</p>
</dd>
<dt><code>%p</code></dt>
<dd><p>Locale’s AM or PM.
</p>
</dd>
<dt><code>%r</code></dt>
<dd><p>Time, 12-hour (hh:mm:ss [AP]M).
</p>
</dd>
<dt><code>%R</code></dt>
<dd><p>Time, 24-hour (hh:mm).
</p>
</dd>
<dt><code>%s</code></dt>
<dd><p>Time in seconds since 00:00:00, Jan 1, 1970 (a nonstandard extension).
</p>
</dd>
<dt><code>%S</code></dt>
<dd><p>Second (00-61).
</p>
</dd>
<dt><code>%T</code></dt>
<dd><p>Time, 24-hour (hh:mm:ss).
</p>
</dd>
<dt><code>%X</code></dt>
<dd><p>Locale’s time representation (%H:%M:%S).
</p>
</dd>
<dt><code>%z</code></dt>
<dd><p>Offset from UTC (±hhmm), or nothing if no time zone is
determinable.
</p>
</dd>
<dt><code>%Z</code></dt>
<dd><p>Time zone (EDT), or nothing if no time zone is determinable.
</p></dd>
</dl>
<p>Date fields:
</p>
<dl compact="compact">
<dt><code>%a</code></dt>
<dd><p>Locale’s abbreviated weekday name (Sun-Sat).
</p>
</dd>
<dt><code>%A</code></dt>
<dd><p>Locale’s full weekday name, variable length (Sunday-Saturday).
</p>
</dd>
<dt><code>%b</code></dt>
<dd><p>Locale’s abbreviated month name (Jan-Dec).
</p>
</dd>
<dt><code>%B</code></dt>
<dd><p>Locale’s full month name, variable length (January-December).
</p>
</dd>
<dt><code>%c</code></dt>
<dd><p>Locale’s date and time (Sat Nov 04 12:02:33 EST 1989).
</p>
</dd>
<dt><code>%C</code></dt>
<dd><p>Century (00-99).
</p>
</dd>
<dt><code>%d</code></dt>
<dd><p>Day of month (01-31).
</p>
</dd>
<dt><code>%e</code></dt>
<dd><p>Day of month ( 1-31).
</p>
</dd>
<dt><code>%D</code></dt>
<dd><p>Date (mm/dd/yy).
</p>
</dd>
<dt><code>%h</code></dt>
<dd><p>Same as %b.
</p>
</dd>
<dt><code>%j</code></dt>
<dd><p>Day of year (001-366).
</p>
</dd>
<dt><code>%m</code></dt>
<dd><p>Month (01-12).
</p>
</dd>
<dt><code>%U</code></dt>
<dd><p>Week number of year with Sunday as first day of week (00-53).
</p>
</dd>
<dt><code>%w</code></dt>
<dd><p>Day of week (0-6).
</p>
</dd>
<dt><code>%W</code></dt>
<dd><p>Week number of year with Monday as first day of week (00-53).
</p>
</dd>
<dt><code>%x</code></dt>
<dd><p>Locale’s date representation (mm/dd/yy).
</p>
</dd>
<dt><code>%y</code></dt>
<dd><p>Last two digits of year (00-99).
</p>
</dd>
<dt><code>%Y</code></dt>
<dd><p>Year (1970-).
</p></dd>
</dl>
<p><strong>See also:</strong> <a href="#XREFstrptime">strptime</a>, <a href="#XREFlocaltime">localtime</a>, <a href="#XREFgmtime">gmtime</a>, <a href="#XREFmktime">mktime</a>, <a href="#XREFtime">time</a>, <a href="#XREFnow">now</a>, <a href="#XREFdate">date</a>, <a href="#XREFclock">clock</a>, <a href="#XREFdatenum">datenum</a>, <a href="#XREFdatestr">datestr</a>, <a href="#XREFdatevec">datevec</a>, <a href="#XREFcalendar">calendar</a>, <a href="#XREFweekday">weekday</a>.
</p></dd></dl>
<a name="XREFstrptime"></a><dl>
<dt><a name="index-strptime"></a><em>[<var>tm_struct</var>, <var>nchars</var>] =</em> <strong>strptime</strong> <em>(<var>str</var>, <var>fmt</var>)</em></dt>
<dd><p>Convert the string <var>str</var> to the time structure <var>tm_struct</var> under
the control of the format string <var>fmt</var>.
</p>
<p>If <var>fmt</var> fails to match, <var>nchars</var> is 0; otherwise, it is set to the
position of last matched character plus 1. Always check for this unless
you’re absolutely sure the date string will be parsed correctly.
</p>
<p><strong>See also:</strong> <a href="#XREFstrftime">strftime</a>, <a href="#XREFlocaltime">localtime</a>, <a href="#XREFgmtime">gmtime</a>, <a href="#XREFmktime">mktime</a>, <a href="#XREFtime">time</a>, <a href="#XREFnow">now</a>, <a href="#XREFdate">date</a>, <a href="#XREFclock">clock</a>, <a href="#XREFdatenum">datenum</a>, <a href="#XREFdatestr">datestr</a>, <a href="#XREFdatevec">datevec</a>, <a href="#XREFcalendar">calendar</a>, <a href="#XREFweekday">weekday</a>.
</p></dd></dl>
<p>Most of the remaining functions described in this section are not
patterned after the standard C library. Some are available for
compatibility with <small>MATLAB</small> and others are provided because they are
useful.
</p>
<a name="XREFclock"></a><dl>
<dt><a name="index-clock"></a><em></em> <strong>clock</strong> <em>()</em></dt>
<dd><p>Return the current local date and time as a date vector.
</p>
<p>The date vector contains the following fields: current year, month (1-12),
day (1-31), hour (0-23), minute (0-59), and second (0-61). The seconds
field has a fractional part after the decimal point for extended accuracy.
</p>
<p>For example:
</p>
<div class="example">
<pre class="example">fix (clock ())
⇒ 1993 8 20 4 56 1
</pre></div>
<p><code>clock</code> is more accurate on systems that have the <code>gettimeofday</code>
function.
</p>
<p><strong>See also:</strong> <a href="#XREFnow">now</a>, <a href="#XREFdate">date</a>, <a href="#XREFdatevec">datevec</a>.
</p></dd></dl>
<a name="XREFdate"></a><dl>
<dt><a name="index-date"></a><em></em> <strong>date</strong> <em>()</em></dt>
<dd><p>Return the current date as a character string in the form DD-MMM-YYYY.
</p>
<p>For example:
</p>
<div class="example">
<pre class="example">date ()
⇒ 20-Aug-1993
</pre></div>
<p><strong>See also:</strong> <a href="#XREFnow">now</a>, <a href="#XREFclock">clock</a>, <a href="#XREFdatestr">datestr</a>, <a href="#XREFlocaltime">localtime</a>.
</p></dd></dl>
<a name="XREFetime"></a><dl>
<dt><a name="index-etime"></a><em></em> <strong>etime</strong> <em>(<var>t2</var>, <var>t1</var>)</em></dt>
<dd><p>Return the difference in seconds between two time values returned from
<code>clock</code> (<em><var>t2</var> - <var>t1</var></em>).
</p>
<p>For example:
</p>
<div class="example">
<pre class="example">t0 = clock ();
# many computations later…
elapsed_time = etime (clock (), t0);
</pre></div>
<p>will set the variable <code>elapsed_time</code> to the number of seconds since the
variable <code>t0</code> was set.
</p>
<p><strong>See also:</strong> <a href="#XREFtic">tic</a>, <a href="#XREFtoc">toc</a>, <a href="#XREFclock">clock</a>, <a href="#XREFcputime">cputime</a>, <a href="#XREFaddtodate">addtodate</a>.
</p></dd></dl>
<a name="XREFcputime"></a><dl>
<dt><a name="index-cputime"></a><em>[<var>total</var>, <var>user</var>, <var>system</var>] =</em> <strong>cputime</strong> <em>();</em></dt>
<dd><p>Return the CPU time used by your Octave session.
</p>
<p>The first output is the total time spent executing your process and is equal
to the sum of second and third outputs, which are the number of CPU seconds
spent executing in user mode and the number of CPU seconds spent executing
in system mode, respectively.
</p>
<p>If your system does not have a way to report CPU time usage, <code>cputime</code>
returns 0 for each of its output values.
</p>
<p>Note that because Octave used some CPU time to start, it is reasonable
to check to see if <code>cputime</code> works by checking to see if the total
CPU time used is nonzero.
</p>
<p><strong>See also:</strong> <a href="#XREFtic">tic</a>, <a href="#XREFtoc">toc</a>.
</p></dd></dl>
<a name="XREFis_005fleap_005fyear"></a><dl>
<dt><a name="index-is_005fleap_005fyear"></a><em></em> <strong>is_leap_year</strong> <em>()</em></dt>
<dt><a name="index-is_005fleap_005fyear-1"></a><em></em> <strong>is_leap_year</strong> <em>(<var>year</var>)</em></dt>
<dd><p>Return true if <var>year</var> is a leap year and false otherwise.
</p>
<p>If no year is specified, <code>is_leap_year</code> uses the current year.
</p>
<p>For example:
</p>
<div class="example">
<pre class="example">is_leap_year (2000)
⇒ 1
</pre></div>
<p><strong>See also:</strong> <a href="#XREFweekday">weekday</a>, <a href="#XREFeomday">eomday</a>, <a href="#XREFcalendar">calendar</a>.
</p></dd></dl>
<a name="XREFtic"></a><dl>
<dt><a name="index-tic"></a><em></em> <strong>tic</strong> <em>()</em></dt>
<dt><a name="index-tic-1"></a><em><var>id</var> =</em> <strong>tic</strong> <em>()</em></dt>
<dd><p>Initialize a wall-clock timer.
</p>
<p>Calling <code>tic</code> without an output argument resets the internal timer.
Subsequent calls to <code>toc</code> return the number of seconds since the timer was
set.
</p>
<p>If called with one output argument, <code>tic</code> creates a new timer instance and
returns a timer identifier <var>id</var>. The <var>id</var> is a scalar of type
<code>uint64</code> that may be passed to <code>toc</code> to check elapsed time on this
timer, rather than the default internal timer.
</p>
<p>Example 1 : benchmarking code with internal timer
</p>
<div class="example">
<pre class="example">tic;
# many computations later…
elapsed_time = toc;
</pre></div>
<p>Example 2 : mixed timer id and internal timer
</p>
<div class="example">
<pre class="example">tic;
pause (1);
toc
⇒ Elapsed time is 1.0089 seconds.
id = tic;
pause (2);
toc (id)
⇒ Elapsed time is 2.01142 seconds.
toc
Elapsed time is 3.02308 seconds.
</pre></div>
<p>Calling <code>tic</code> and <code>toc</code> in this way allows nested timing calls.
</p>
<p>If you are more interested in the CPU time that your process used, you should
use the <code>cputime</code> function instead. The <code>tic</code> and <code>toc</code>
functions report the actual wall clock time that elapsed between the calls.
This may include time spent processing other jobs or doing nothing at all.
</p>
<p><strong>See also:</strong> <a href="#XREFtoc">toc</a>, <a href="#XREFcputime">cputime</a>.
</p></dd></dl>
<a name="XREFtoc"></a><dl>
<dt><a name="index-toc"></a><em></em> <strong>toc</strong> <em>()</em></dt>
<dt><a name="index-toc-1"></a><em></em> <strong>toc</strong> <em>(<var>id</var>)</em></dt>
<dt><a name="index-toc-2"></a><em><var>elapsed_time</var> =</em> <strong>toc</strong> <em>(…)</em></dt>
<dd><p>Measure elapsed time on a wall-clock timer.
</p>
<p>With no arguments, return the number of seconds elapsed on the internal timer
since the last call to <code>tic</code>.
</p>
<p>When given the identifier <var>id</var> of a specific timer, return the number of
seconds elapsed since the timer <var>id</var> was initialized.
</p>
<p>See <a href="#XREFtic">tic</a>, for examples of the use of <code>tic</code>/<code>toc</code>.
</p>
<p><strong>See also:</strong> <a href="#XREFtic">tic</a>, <a href="#XREFcputime">cputime</a>.
</p></dd></dl>
<a name="XREFpause"></a><dl>
<dt><a name="index-pause-2"></a><em></em> <strong>pause</strong> <em>()</em></dt>
<dt><a name="index-pause-3"></a><em></em> <strong>pause</strong> <em>(<var>n</var>)</em></dt>
<dt><a name="index-pause-4"></a><em><var>old_state</var> =</em> <strong>pause</strong> <em>("on")</em></dt>
<dt><a name="index-pause-5"></a><em><var>old_state</var> =</em> <strong>pause</strong> <em>("off")</em></dt>
<dt><a name="index-pause-6"></a><em><var>old_state</var> =</em> <strong>pause</strong> <em>("query")</em></dt>
<dd><p>Suspend the execution of the program or change the state of the pause function.
</p>
<p>If invoked without an input arguments then the program is suspended until a
character is typed. If argument <var>n</var> is a positive real value, it indicates
the number of seconds the program shall be suspended, for example:
</p>
<div class="example">
<pre class="example">tic; pause (0.05); toc
-| Elapsed time is 0.05039 seconds.
</pre></div>
<p>The following example prints a message and then waits 5 seconds before
clearing the screen.
</p>
<div class="example">
<pre class="example">disp ("wait please...");
pause (5);
clc;
</pre></div>
<p>If invoked with a string argument <code>"on"</code>, <code>"off"</code>, or
<code>"query"</code>, the state of the pause function is changed or queried. When
the state is <code>"off"</code>, the pause function returns immediately. The
optional return value contains the previous state of the pause function. In
the following example pause is disabled locally:
</p>
<div class="example">
<pre class="example">old_state = pause ("off");
tic; pause (0.05); toc
-| Elapsed time is 3.00407e-05 seconds.
pause (old_state);
</pre></div>
<p>While the program is suspended Octave still handles figures painting and
graphics callbacks execution.
</p>
<p><strong>See also:</strong> <a href="Terminal-Input.html#XREFkbhit">kbhit</a>.
</p></dd></dl>
<a name="XREFdatenum"></a><dl>
<dt><a name="index-datenum"></a><em><var>days</var> =</em> <strong>datenum</strong> <em>(<var>datevec</var>)</em></dt>
<dt><a name="index-datenum-1"></a><em><var>days</var> =</em> <strong>datenum</strong> <em>(<var>year</var>, <var>month</var>, <var>day</var>)</em></dt>
<dt><a name="index-datenum-2"></a><em><var>days</var> =</em> <strong>datenum</strong> <em>(<var>year</var>, <var>month</var>, <var>day</var>, <var>hour</var>)</em></dt>
<dt><a name="index-datenum-3"></a><em><var>days</var> =</em> <strong>datenum</strong> <em>(<var>year</var>, <var>month</var>, <var>day</var>, <var>hour</var>, <var>minute</var>)</em></dt>
<dt><a name="index-datenum-4"></a><em><var>days</var> =</em> <strong>datenum</strong> <em>(<var>year</var>, <var>month</var>, <var>day</var>, <var>hour</var>, <var>minute</var>, <var>second</var>)</em></dt>
<dt><a name="index-datenum-5"></a><em><var>days</var> =</em> <strong>datenum</strong> <em>("datestr")</em></dt>
<dt><a name="index-datenum-6"></a><em><var>days</var> =</em> <strong>datenum</strong> <em>("datestr", <var>f</var>)</em></dt>
<dt><a name="index-datenum-7"></a><em><var>days</var> =</em> <strong>datenum</strong> <em>("datestr", <var>p</var>)</em></dt>
<dt><a name="index-datenum-8"></a><em>[<var>days</var>, <var>secs</var>] =</em> <strong>datenum</strong> <em>(…)</em></dt>
<dd><p>Return the date/time input as a serial day number, with Jan 1, 0000
defined as day 1.
</p>
<p>The integer part, <code>floor (<var>days</var>)</code> counts the number of
complete days in the date input.
</p>
<p>The fractional part, <code>rem (<var>days</var>, 1)</code> corresponds to the time
on the given day.
</p>
<p>The input may be a date vector (see <code>datevec</code>),
datestr (see <code>datestr</code>), or directly specified as input.
</p>
<p>When processing input datestrings, <var>f</var> is the format string used to
interpret date strings (see <code>datestr</code>). If no format <var>f</var> is
specified, then a relatively slow search is performed through various
formats. It is always preferable to specify the format string <var>f</var> if
it is known. Formats which do not specify a particular time component
will have the value set to zero. Formats which do not specify a date
will default to January 1st of the current year.
</p>
<p><var>p</var> is the year at the start of the century to which two-digit years
will be referenced. If not specified, it defaults to the current year
minus 50.
</p>
<p>The optional output <var>secs</var> holds the time on the specified day with
greater precision than <var>days</var>.
</p>
<p>Notes:
</p>
<ul>
<li> Years can be negative and/or fractional.
</li><li> Months below 1 are considered to be January.
</li><li> Days of the month start at 1.
</li><li> Days beyond the end of the month go into subsequent months.
</li><li> Days before the beginning of the month go to the previous month.
</li><li> Days can be fractional.
</li></ul>
<p><strong>Caution:</strong> datenums represent a specific time for the Earth as a
a whole. They do not take in to account time zones (shifts in time based
on location), nor seasonal changes due to Daylight Savings Time (shifts in
time based on local regulation). Be aware that it is possible to create
datenums that, when interpreted by a function which accounts for time zone
and DST shifts such as <code>datestr</code>, are nonexistent or ambiguous.
</p>
<p><strong>Caution:</strong> this function does not attempt to handle Julian calendars
so dates before October 15, 1582 are wrong by as much as eleven days. Also,
be aware that only Roman Catholic countries adopted the calendar in 1582.
It took until 1924 for it to be adopted everywhere. See the Wikipedia entry
on the Gregorian calendar for more details.
</p>
<p><strong>Warning:</strong> leap seconds are ignored. A table of leap seconds is
available on the Wikipedia entry for leap seconds.
</p>
<p><strong>See also:</strong> <a href="#XREFdatestr">datestr</a>, <a href="#XREFdatevec">datevec</a>, <a href="#XREFnow">now</a>, <a href="#XREFclock">clock</a>, <a href="#XREFdate">date</a>.
</p></dd></dl>
<a name="XREFdatestr"></a><dl>
<dt><a name="index-datestr"></a><em><var>str</var> =</em> <strong>datestr</strong> <em>(<var>date</var>)</em></dt>
<dt><a name="index-datestr-1"></a><em><var>str</var> =</em> <strong>datestr</strong> <em>(<var>date</var>, <var>f</var>)</em></dt>
<dt><a name="index-datestr-2"></a><em><var>str</var> =</em> <strong>datestr</strong> <em>(<var>date</var>, <var>f</var>, <var>p</var>)</em></dt>
<dd><p>Format the given date/time according to the format <var>f</var> and return
the result in <var>str</var>.
</p>
<p><var>date</var> is a serial date number (see <code>datenum</code>), a date vector (see
<code>datevec</code>), or a string or cell array of strings. In the latter case,
it is passed to <code>datevec</code> to guess the input date format.
</p>
<p><var>f</var> can be an integer which corresponds to one of the codes in the table
below, or a date format string.
</p>
<p><var>p</var> is the year at the start of the century in which two-digit years are
to be interpreted in. If not specified, it defaults to the current year
minus 50.
</p>
<p>For example, the date 730736.65149 (2000-09-07 15:38:09.0934) would be
formatted as follows:
</p>
<table>
<thead><tr><th width="10%">Code</th><th width="45%">Format</th><th width="35%">Example</th></tr></thead>
<tr><td width="10%">0</td><td width="45%">dd-mmm-yyyy HH:MM:SS</td><td width="35%">07-Sep-2000 15:38:09</td></tr>
<tr><td width="10%">1</td><td width="45%">dd-mmm-yyyy</td><td width="35%">07-Sep-2000</td></tr>
<tr><td width="10%">2</td><td width="45%">mm/dd/yy</td><td width="35%">09/07/00</td></tr>
<tr><td width="10%">3</td><td width="45%">mmm</td><td width="35%">Sep</td></tr>
<tr><td width="10%">4</td><td width="45%">m</td><td width="35%">S</td></tr>
<tr><td width="10%">5</td><td width="45%">mm</td><td width="35%">09</td></tr>
<tr><td width="10%">6</td><td width="45%">mm/dd</td><td width="35%">09/07</td></tr>
<tr><td width="10%">7</td><td width="45%">dd</td><td width="35%">07</td></tr>
<tr><td width="10%">8</td><td width="45%">ddd</td><td width="35%">Thu</td></tr>
<tr><td width="10%">9</td><td width="45%">d</td><td width="35%">T</td></tr>
<tr><td width="10%">10</td><td width="45%">yyyy</td><td width="35%">2000</td></tr>
<tr><td width="10%">11</td><td width="45%">yy</td><td width="35%">00</td></tr>
<tr><td width="10%">12</td><td width="45%">mmmyy</td><td width="35%">Sep00</td></tr>
<tr><td width="10%">13</td><td width="45%">HH:MM:SS</td><td width="35%">15:38:09</td></tr>
<tr><td width="10%">14</td><td width="45%">HH:MM:SS PM</td><td width="35%">3:38:09 PM</td></tr>
<tr><td width="10%">15</td><td width="45%">HH:MM</td><td width="35%">15:38</td></tr>
<tr><td width="10%">16</td><td width="45%">HH:MM PM</td><td width="35%">3:38 PM</td></tr>
<tr><td width="10%">17</td><td width="45%">QQ-YY</td><td width="35%">Q3-00</td></tr>
<tr><td width="10%">18</td><td width="45%">QQ</td><td width="35%">Q3</td></tr>
<tr><td width="10%">19</td><td width="45%">dd/mm</td><td width="35%">07/09</td></tr>
<tr><td width="10%">20</td><td width="45%">dd/mm/yy</td><td width="35%">07/09/00</td></tr>
<tr><td width="10%">21</td><td width="45%">mmm.dd,yyyy HH:MM:SS</td><td width="35%">Sep.07,2000 15:38:08</td></tr>
<tr><td width="10%">22</td><td width="45%">mmm.dd,yyyy</td><td width="35%">Sep.07,2000</td></tr>
<tr><td width="10%">23</td><td width="45%">mm/dd/yyyy</td><td width="35%">09/07/2000</td></tr>
<tr><td width="10%">24</td><td width="45%">dd/mm/yyyy</td><td width="35%">07/09/2000</td></tr>
<tr><td width="10%">25</td><td width="45%">yy/mm/dd</td><td width="35%">00/09/07</td></tr>
<tr><td width="10%">26</td><td width="45%">yyyy/mm/dd</td><td width="35%">2000/09/07</td></tr>
<tr><td width="10%">27</td><td width="45%">QQ-YYYY</td><td width="35%">Q3-2000</td></tr>
<tr><td width="10%">28</td><td width="45%">mmmyyyy</td><td width="35%">Sep2000</td></tr>
<tr><td width="10%">29</td><td width="45%">yyyy-mm-dd</td><td width="35%">2000-09-07</td></tr>
<tr><td width="10%">30</td><td width="45%">yyyymmddTHHMMSS</td><td width="35%">20000907T153808</td></tr>
<tr><td width="10%">31</td><td width="45%">yyyy-mm-dd HH:MM:SS</td><td width="35%">2000-09-07 15:38:08</td></tr>
</table>
<p>If <var>f</var> is a format string, the following symbols are recognized:
</p>
<table>
<thead><tr><th width="10%">Symbol</th><th width="70%">Meaning</th><th width="20%">Example</th></tr></thead>
<tr><td width="10%">yyyy</td><td width="70%">Full year</td><td width="20%">2005</td></tr>
<tr><td width="10%">yy</td><td width="70%">Two-digit year</td><td width="20%">05</td></tr>
<tr><td width="10%">mmmm</td><td width="70%">Full month name</td><td width="20%">December</td></tr>
<tr><td width="10%">mmm</td><td width="70%">Abbreviated month name</td><td width="20%">Dec</td></tr>
<tr><td width="10%">mm</td><td width="70%">Numeric month number (padded with zeros)</td><td width="20%">01, 08, 12</td></tr>
<tr><td width="10%">m</td><td width="70%">First letter of month name (capitalized)</td><td width="20%">D</td></tr>
<tr><td width="10%">dddd</td><td width="70%">Full weekday name</td><td width="20%">Sunday</td></tr>
<tr><td width="10%">ddd</td><td width="70%">Abbreviated weekday name</td><td width="20%">Sun</td></tr>
<tr><td width="10%">dd</td><td width="70%">Numeric day of month (padded with zeros)</td><td width="20%">11</td></tr>
<tr><td width="10%">d</td><td width="70%">First letter of weekday name (capitalized)</td><td width="20%">S</td></tr>
<tr><td width="10%">HH</td><td width="70%">Hour of day, padded with zeros,</td><td width="20%">09:00</td></tr>
<tr><td width="10%"></td><td width="70%">or padded with spaces if PM is set</td><td width="20%">9:00 AM</td></tr>
<tr><td width="10%">MM</td><td width="70%">Minute of hour (padded with zeros)</td><td width="20%">10:05</td></tr>
<tr><td width="10%">SS</td><td width="70%">Second of minute (padded with zeros)</td><td width="20%">10:05:03</td></tr>
<tr><td width="10%">FFF</td><td width="70%">Milliseconds of second (padded with zeros)</td><td width="20%">10:05:03.012</td></tr>
<tr><td width="10%">AM</td><td width="70%">Use 12-hour time format</td><td width="20%">11:30 AM</td></tr>
<tr><td width="10%">PM</td><td width="70%">Use 12-hour time format</td><td width="20%">11:30 PM</td></tr>
</table>
<p>If <var>f</var> is not specified or is <code>-1</code>, then use 0, 1 or 16, depending
on whether the date portion or the time portion of <var>date</var> is empty.
</p>
<p>If <var>p</var> is nor specified, it defaults to the current year minus 50.
</p>
<p>If a matrix or cell array of dates is given, a column vector of date strings
is returned.
</p>
<p><strong>See also:</strong> <a href="#XREFdatenum">datenum</a>, <a href="#XREFdatevec">datevec</a>, <a href="#XREFdate">date</a>, <a href="#XREFnow">now</a>, <a href="#XREFclock">clock</a>.
</p></dd></dl>
<a name="XREFdatevec"></a><dl>
<dt><a name="index-datevec"></a><em><var>v</var> =</em> <strong>datevec</strong> <em>(<var>date</var>)</em></dt>
<dt><a name="index-datevec-1"></a><em><var>v</var> =</em> <strong>datevec</strong> <em>(<var>date</var>, <var>f</var>)</em></dt>
<dt><a name="index-datevec-2"></a><em><var>v</var> =</em> <strong>datevec</strong> <em>(<var>date</var>, <var>p</var>)</em></dt>
<dt><a name="index-datevec-3"></a><em><var>v</var> =</em> <strong>datevec</strong> <em>(<var>date</var>, <var>f</var>, <var>p</var>)</em></dt>
<dt><a name="index-datevec-4"></a><em>[<var>y</var>, <var>m</var>, <var>d</var>, <var>h</var>, <var>mi</var>, <var>s</var>] =</em> <strong>datevec</strong> <em>(…)</em></dt>
<dd><p>Convert a serial date number (see <code>datenum</code>) or date string (see
<code>datestr</code>) into a date vector.
</p>
<p>A date vector is a row vector with six members, representing the year,
month, day, hour, minute, and seconds respectively.
</p>
<p><var>f</var> is the format string used to interpret date strings
(see <code>datestr</code>). If <var>date</var> is a string, but no format is
specified, then a relatively slow search is performed through various
formats. It is always preferable to specify the format string <var>f</var> if it
is known. Formats which do not specify a particular time component will
have the value set to zero. Formats which do not specify a date will
default to January 1st of the current year.
</p>
<p><var>p</var> is the year at the start of the century to which two-digit years
will be referenced. If not specified, it defaults to the current year minus
50.
</p>
<p><strong>See also:</strong> <a href="#XREFdatenum">datenum</a>, <a href="#XREFdatestr">datestr</a>, <a href="#XREFclock">clock</a>, <a href="#XREFnow">now</a>, <a href="#XREFdate">date</a>.
</p></dd></dl>
<a name="XREFaddtodate"></a><dl>
<dt><a name="index-addtodate"></a><em><var>d</var> =</em> <strong>addtodate</strong> <em>(<var>d</var>, <var>q</var>, <var>f</var>)</em></dt>
<dd><p>Add <var>q</var> amount of time (with units <var>f</var>) to the serial datenum,
<var>d</var>.
</p>
<p><var>f</var> must be one of <code>"year"</code>, <code>"month"</code>, <code>"day"</code>,
<code>"hour"</code>, <code>"minute"</code>, <code>"second"</code>, or
<code>"millisecond"</code>.
</p>
<p><strong>See also:</strong> <a href="#XREFdatenum">datenum</a>, <a href="#XREFdatevec">datevec</a>, <a href="#XREFetime">etime</a>.
</p></dd></dl>
<a name="XREFcalendar"></a><dl>
<dt><a name="index-calendar"></a><em><var>c</var> =</em> <strong>calendar</strong> <em>()</em></dt>
<dt><a name="index-calendar-1"></a><em><var>c</var> =</em> <strong>calendar</strong> <em>(<var>d</var>)</em></dt>
<dt><a name="index-calendar-2"></a><em><var>c</var> =</em> <strong>calendar</strong> <em>(<var>y</var>, <var>m</var>)</em></dt>
<dt><a name="index-calendar-3"></a><em></em> <strong>calendar</strong> <em>(…)</em></dt>
<dd><p>Return the current monthly calendar in a 6x7 matrix.
</p>
<p>If <var>d</var> is specified, return the calendar for the month containing the
date <var>d</var>, which must be a serial date number or a date string.
</p>
<p>If <var>y</var> and <var>m</var> are specified, return the calendar for year <var>y</var>
and month <var>m</var>.
</p>
<p>If no output arguments are specified, print the calendar on the screen
instead of returning a matrix.
</p>
<p><strong>See also:</strong> <a href="#XREFdatenum">datenum</a>, <a href="#XREFdatestr">datestr</a>.
</p></dd></dl>
<a name="XREFweekday"></a><dl>
<dt><a name="index-weekday"></a><em>[<var>n</var>, <var>s</var>] =</em> <strong>weekday</strong> <em>(<var>d</var>)</em></dt>
<dt><a name="index-weekday-1"></a><em>[<var>n</var>, <var>s</var>] =</em> <strong>weekday</strong> <em>(<var>d</var>, <var>format</var>)</em></dt>
<dd><p>Return the day of the week as a number in <var>n</var> and as a string in
<var>s</var>.
</p>
<p>The days of the week are numbered 1–7 with the first day being Sunday.
</p>
<p><var>d</var> is a serial date number or a date string.
</p>
<p>If the string <var>format</var> is not present or is equal to <code>"short"</code>
then <var>s</var> will contain the abbreviated name of the weekday. If
<var>format</var> is <code>"long"</code> then <var>s</var> will contain the full name.
</p>
<p>Table of return values based on <var>format</var>:
</p>
<table>
<thead><tr><th width="6%"><var>n</var></th><th width="13%"><code>"short"</code></th><th width="16%"><code>"long"</code></th></tr></thead>
<tr><td width="6%">1</td><td width="13%">Sun</td><td width="16%">Sunday</td></tr>
<tr><td width="6%">2</td><td width="13%">Mon</td><td width="16%">Monday</td></tr>
<tr><td width="6%">3</td><td width="13%">Tue</td><td width="16%">Tuesday</td></tr>
<tr><td width="6%">4</td><td width="13%">Wed</td><td width="16%">Wednesday</td></tr>
<tr><td width="6%">5</td><td width="13%">Thu</td><td width="16%">Thursday</td></tr>
<tr><td width="6%">6</td><td width="13%">Fri</td><td width="16%">Friday</td></tr>
<tr><td width="6%">7</td><td width="13%">Sat</td><td width="16%">Saturday</td></tr>
</table>
<p><strong>See also:</strong> <a href="#XREFeomday">eomday</a>, <a href="#XREFis_005fleap_005fyear">is_leap_year</a>, <a href="#XREFcalendar">calendar</a>, <a href="#XREFdatenum">datenum</a>, <a href="#XREFdatevec">datevec</a>.
</p></dd></dl>
<a name="XREFeomday"></a><dl>
<dt><a name="index-eomday"></a><em><var>e</var> =</em> <strong>eomday</strong> <em>(<var>y</var>, <var>m</var>)</em></dt>
<dd><p>Return the last day of the month <var>m</var> for the year <var>y</var>.
</p>
<p><strong>See also:</strong> <a href="#XREFweekday">weekday</a>, <a href="#XREFdatenum">datenum</a>, <a href="#XREFdatevec">datevec</a>, <a href="#XREFis_005fleap_005fyear">is_leap_year</a>, <a href="#XREFcalendar">calendar</a>.
</p></dd></dl>
<a name="XREFdatetick"></a><dl>
<dt><a name="index-datetick"></a><em></em> <strong>datetick</strong> <em>()</em></dt>
<dt><a name="index-datetick-1"></a><em></em> <strong>datetick</strong> <em>(<var>axis_str</var>)</em></dt>
<dt><a name="index-datetick-2"></a><em></em> <strong>datetick</strong> <em>(<var>date_format</var>)</em></dt>
<dt><a name="index-datetick-3"></a><em></em> <strong>datetick</strong> <em>(<var>axis_str</var>, <var>date_format</var>)</em></dt>
<dt><a name="index-datetick-4"></a><em></em> <strong>datetick</strong> <em>(…, "keeplimits")</em></dt>
<dt><a name="index-datetick-5"></a><em></em> <strong>datetick</strong> <em>(…, "keepticks")</em></dt>
<dt><a name="index-datetick-6"></a><em></em> <strong>datetick</strong> <em>(<var>hax</var>, …)</em></dt>
<dd><p>Add date-formatted tick labels to an axis.
</p>
<p>The axis to apply the ticks to is determined by <var>axis_str</var> which can
take the values <code>"x"</code>, <code>"y"</code>, or <code>"z"</code>. The default
value is <code>"x"</code>.
</p>
<p>The formatting of the labels is determined by the variable
<var>date_format</var>, which can either be a string or positive integer that
<code>datestr</code> accepts.
</p>
<p>If the first argument <var>hax</var> is an axes handle, then plot into this axes,
rather than the current axes returned by <code>gca</code>.
</p>
<p><strong>See also:</strong> <a href="#XREFdatenum">datenum</a>, <a href="#XREFdatestr">datestr</a>.
</p></dd></dl>
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